Bearing construction



May 16, 1944- P. M. sAMPA'rAcos s 2,348,928

BEARING CONSTRUCTION 'y Filed Nov. 15,' 1941 2 sheets-sheet 1 "wh Il l11 a a 31.27%* 7n.

May 16, 1944. P. M. sAMPATAcos 1 2,348,928

` l BEARING CONSTRUCTION E iled Nqv. 15, 1941 v l 2 sheets-sheet 2 QI//fI I Feer'm. Sam ecos Patented May 16, 1944 UNITED STATES PATENT OFFICEv2,948,922; BEARING CONSTRUCTION Peter M. Sampatacos, Worcester, Mass.,assigner to The Heald Machine Company, Worcester,

Mass., a corporation of Massachusetts Appuunn November 1a, 1941,` serialNo. 418,956

7 claims. (ol. sos-73) The present invention relates to bearingconstructions, and more particularly to a bearing of the so-calledMicheli type,- wherein the rotary memberis surrounded' and supported bya plurality Ofsegmental rockable shoes. Such rocktendencies, especiallybetween the shoes of suchv Fig. 8 is a sectional view on line 8-8 ofFig. 7, and

Fig. 9 is a fragmentary sectional view illustrating a modification ofthe mounting or backing member for each bearing shoe. A

Like reference characters refer to like parts in the different figures.

a bearing, toward turbulence and cavitation ofv the film-forminglubricant, that may seriously detract from the bearings stability inoperation; l and it is proposed in said patent to minimize suchinstability by maintaining a substantial pressure upon a body of saidlubricant that completely submerges all of the rockable shoes.

According to my invention as hereinafter described, such tendenciestoward turbulence and cavitation in the film-forming lubricant areefi'ectually overcome in the spaces between the rocker shoes by soshaping the ends or edges of the shoes themselves, as to insure at alltimes a free and uniform ilow of the lubricant into the wedge-shapedclearance space formed by each shoe with the surface of the rotatingshaft or spindle. My invention also obtains increased stability of eachshoe by an improved Vpivotal mounting therefor. Other and furtherobjects and advantages of my invention will more fully appear fromv thefollowing detailed description thereof, taken in connection with theaccompanying drawings in which y Fig. 1 is a fragmentary cross-sectionalview illustrating the conventional construction and arrangement ofrocker shoesin bearings of the type above mentioned.

Figs. 2 and 3 are views similar to Fig. 1, illustrating the constructionand mounting of the rocker shoes according-to my invention.

Fig. 4 is a longitudinal sectional view on line li-I of Fig. 5illustrating an application of myv improved bearings to a tool head.

sectional view on line 5 5 of In the conventional rocker-shoe bearingarrangementshown by Fig. 1, the rotary member or shaft I is surrounded,in the bore 2 of its supporting housing 3, by a series of segmentalshoes 4, I, each of the latter providing an inner bearing surface on aradius of curvature substantially the sameas that of the surface ofshaft i. Each shoe 4 is so mounted in bore 2 that it can have limitedrocking movement on an axis, substantially paralleling the shaft axis;in the conventional arrangement shown alike by Fig. 1 and by theaforesaid Dall and Ernst patent, the pivot for each shoe (customarilysomewhat nearer the trailing end 5 than the leading end 6) is providedby a pin 'l projecting from an adjustable screw 8 carried by housing 3,and entered loosely in a recess 9 of the associated shoe. permit aslight clearance between the inner surface of each shoe l and the outersurface of shaft I; assuming the latter to rotate in the direction ofthe arrow, Fig. l, each shoe, when the shaft runs partly or whollysubmerged in oil, is supposed to assume and maintain a position (shownexaggeratedly by Fig. 1), with its longer leading portion toward end v6slightly spaced from the shaft whereas the trailing end should almostcontact the shaft; these positions provide around the shaft thedesiredplurality of tapering or wedge-shaped lubrication pockets lli, I0 thatare relied upon to maintain the oil lm in the absence of 'metal-to-metalcontact, and to resist undue displacement of the shaft axis.

In such bearings, the lm of oil is carried around bythe rotating shaft,and the desired action of the rocking shoes is largely dependent upon afree and uniform inflow of said oil into the inlet or leading ends ofthe several wedge-shaped pockets formed by the shoes. On account of thecentrifugal force effective on said oil, and also the turbulenceproduced by the escape of said oil from the trailing ends of saidpockets, this free and uniform inflow has been diilicult of achievement;inthe aforesaid Dall and Ernst patent it is sought to combat the eiectsof centrifugal force and turbulence as well as of cavivtation bycompletely submerging the rocker shoes in a body. of oil on whichasubstantial pressure is maintained.

-The screws 8 I have discovered that the rocker shoes themselves can beso constructed and mounted as to avoid the effects of centrifugal force,turbulence and cavitation on the oil in the zones that contain theopposed ends or edges of adjacent rocker shoes. According to myinvention, as shown in Fig. 2, the leading end or edge of each rockershoe II, instead of abruptly opposing (see Fig. 1) the oil escaping fromthe trailing edge of the preceding shoe, presents a convex surface I2that merges smoothly with the inner face of the shoe, said surface I2appearing in cross section as a second degree curve that connects theouter and inner faces of the shoe. Said surface I2 in overhangingrelation to the rotating shaft or spindle i confines the oil emergingfrom beneath the preceding shoe, and secures said oils guidance, with amaterial reduction of turbulence, into the wedgeshaped pocket.

Preferably also, to further reduce turbulence and cavitation in thezones containing the opposed ends of adjacent shoe il, II, each shoe'strailing end or edge as shown in Fig. 3 is formed as a convex surface i3that merges with the inner face of the shoe, and helps to prevent anyabrupt change in the velocity of the oil escaping from beneath saidshoe; the surfaces I2 and i3 of the adjacent shoes are thuscomplementary, in the formation between them of a gap or opening iiiwhich in cross section is of a constricted or venturi form that widensout rapidly toward the surface of rotary element or shaft i, the centerline or axis of this venturi section being nonradial to the rotationalaxis of shaft I in a very marked degree, and the deviation from radialbeing in the direction of said shaft's rotation; this special formationof the space between adjacent shoes il, il operates against undueoutward dispersal of the oil and promotes instead the uniform passage ofsame, by rotation of the shaft. into the wedge-shaped pocket beneatheach shoe.

This uniform and steady passage or the oil on the shafts surface acrossthe space intervening between adjacent rocker, shoes il, il, insuresunimpaired maintenance of the oil lm beneath each l shoe and preventsany metal-to-metal contact of the parts-these results being obtained inmy irnproved bearing by merely supplying lubricant in sufficient amountto partly submerge the shaft, and without any need for completesubmergence of the shoes in a body of the lubricant or for keeping saidlubricant under pressure by means extraneous to the bearing. Because ofthis uni- 'formity of oil-lrn flow and maintenance, the D0 sition ofshaft i, once the shoes il, It have been properly adjusted, isthoroughly stabilized, the oil iilms themselves effectively resistingany shifting tendency of the shaft axis, even under widely varyingconditions of speed and load.

To promote this stability, each shoe II, instead of being pivoted by theconventional pin-andtherein by rapid rotation of the shaft or spindle isconducted away and dissipated through the body or housing 3.

Figs. 4 and 5 illustrate the application of a pair of my improved rockershoe bearings to a tool head,A for the rotative support of a spindle I'carrying at one end a pulley vI9 and at the other end a tool, not shown,such as a grinding wheel or a boring tool. The spindle -I extendsthrough the bore of housing 3', said bore being appropriately recessedat 2', 2 to receive the two sets of rocker shoes Il, il, and there beingequidistant radial tapped holes iii, it intersecting each recess 2', toreceive the adjustable shoe-backing members I'I, il; said holes iii, it,after adjustment of the members il, ill to the desired positions, arepreferably closed by caps 2t, 20 to exclude dirt and to prevent anyescape of lubricant.

The backing members l'i, il of Figs. 4 and 5 are adapted to be locked inthe desired position of adjustment; to this end each member I1 isslotted circumferentially, as shown at 2 I and adjacent its slotreceivesa screw 22, which when tightened down causes the external threads onmember I1 to bind on the threads of tapped hole I8.

iAlthough my improved bearing is intended pri marily to relieve thenecessity of putting the lubricant under pressure, it is recognized thatabnormal cases may arise in which the load on the spindle is so'heavythat the use of lubricant under pressure may be advisable, in order tofurther increase the stability and load capacity of the bearing. Myinvention lends itself most effectively to such pressure lubrication',as shown by Fig. 6, wherein each shoe I I at the bottom of its sphericalrecess or socket provides a space 23, adjacent the inner end of itsbacking member I1', the latter having a central passage 24 connectingsaid inner space23 with an outerspace 25 (inwardly of cap 2U) .in theassociated.tapped hole I8 of housing t". As best shown in Figs. '1 and8, each inner space 2.3 communicates through passages I5, i5 in the shoewith a groove I6 formed in the bearing surface of the shoe andcorresponding substantially in shape or outline to the perimeter of theeffective portion of said surface. As shown in Fig. 6, the several outerspaces 25, 25 are connected by bores 26, 26 of housing 3" with suitablepipes or conduits 27, 28, 29 and 30 leading from a common source P oflubricant under pressure; each of said pipes provides an adjustableresistor of any desired form, as indicated respectively at 3i, 32, 33and 3d, these being subject to manipulation and adjustment forcontrolling the pressure of the lubricant supplied to the groove 46 1oiteach individual shoe, in order to compensate, if need be, for anyabnormal load conditions tending to upset the stability of the bearing.By thus subjecting each shoe substantially in the line of socketmounting l, 9 shown by Fig. l, is preferably y pivoted by a mountingwhich aords ample surface contact between shoe and backing member, withno sacrifice of said shoes ability to aline itself at all times with theshaft. To this end, the outer face of each shoe provides a socket I5 ofsemi-spherical form, adapted to receive 'the matching spherical end I6of a backing member I1, each of the latter beingexternally threaded foradjustment inwardly or outwardly in suitable tapped holes i8 extendingsubstantially radially of the bearing housing 3. Such ball and socketmountings for the rocker shoes eliminate all unnecessary play and giveasubstantial area of con- Mct with each shoe, by which any heatgenerated its support, to the pressure of the lubricant, and by thusdistributing said lubricant across the ends vand along the sides of thewedge-shaped oiliilm pocket between shoe and shaft, I obtain ameasurably greater stability for the shoes than can be obtained bymerely maintaining a pressure on a body of lubricant in the spacecontaining said shoes; moreover, in my improved arrangement shown byFig. 6, the several resistors 3 I, l2, 33 and 34 have, in effect, apronounced dampening action, that overcomes any vibratory tendencies oftheir respective associated shoes. gf;

Fig. 9 illustrates a. modification of the arrangement by ywhich thebacking member for each rocker shoe is locked in its desired positionvofadjustment. In the arrangement shown by Fig. 9 said backing membercomprises two externallythreaded parts 35 and 3B, the former havingballand-socket engagement 3T with the shoe and having a central recess38, with tapered mouth 39 and an inner hexagonal portion Ml, to receivean adjusting wrench, not shown. Radial saw slots di and I2 in member 35enable said member to be expanded by the inward screwing of the othermember 36, the latter having a tapered portion 3 for engagement with thetaper bore 38 of member iii, and having a bore 44 for passage of saidadiusting wrench. After the inner part'35 has been adjusted, said outerpart is screwed inwardly to expand said part 35 and bind its threadsagainst those of the tapped hole i8.

l. In a bearing construction, a rotary member having a bearing surface,means for supplying lubricant thereto, and a plurality of segmentalshoes arranged in a circular series about said surface, each shoe beingmounted for rocking movement to form with said bearing surface awedgeshaped pocket 'for the lubricant lm on said bearing surface, theleading end vof each shoe overhanging the entrance to its pocket andpresenting across substantially the shoe's entire thickness a convex`surface in opposition to the lubricant escaping from beneath thetrailing end of the preceding shoe of said series.

2. In a bearing construction, a rotary member having a bearing surface,means for supplying lubricant thereto, and a ,pluralityl of Y segmentalshoes arranged in a circular series about said surface, each shoe beingmounted for rocking movement to form with said bearing surface awedgeshaped pocket for the lubricant film on said bearing surface, theopposed ends of adjacent shoes ha convex surfaces defining between saidshoes a space or gap whose cross section is of substantially Venturiform, on a center lineor axis that is non-radial to the axis of saidrotary member, whereby to reduce the turbulence of said lubricant inits= passage through the space between said shoes.

v3. VIn a bearing construction, a rotary member I having a bearingsurface, means for supplying lubricant thereto, and a plurality ofsegmental shoes arranged in a circular series about said sury face, eachshoe being mounted for rocking move-v f ment to form with said bearingsurface a wedgeshaped pocket for the lubricant lm on said bearingsurface, the leading end of each shoe 'overhanging the entrance to itspocket and presenting across substantially the shoes entire thickness aconvex surface in opposition to the lubrially adjusting the pressure 4PEIlill'i.

` in each passage.

cant escaping from the pocket of the preceding shoe of the series andthe trailing end of each shoe having a convex surfacecooperating withsaid mst-mentioned convex surface to form bel face. a plurality ofsegmental shoes arranged in' a circular series about said surface, eachslicev being rockable to form with said surface a wedgeshaped lubricantpocket, a backing member for .each shoe having a ball-and-socketconnection therewith, a passage through each backing member to conductlubricant under-pressure to each shoe substantially in the line of itssupport and means for independently adjusting the pressure in eachpassage. v

5. In a bearing of the class described, a rotary.l

member having a bearing surface, a plurality of segmental shoes arrangedin a circular series about said bearing surface, an adjustable backingmember for each shoe providing a' ball-and-socket mounting therefor,permitting rocking of each shoe to'formwith said surface a wedge-shapedlubricant pocket, a lubricant passage throughl each shoe and its backingmember and communieating with the associated pocket, means for sup--plying lubricant under pressurev to the several lubricant passages andmeans for independently adjusting the pressure ineach passage.

6. In a bearing of the class described, a rotary member having a bearingsurface, a plurality of segmental shoes arranged in a circular seriesvabout said bearing surface, an adjustable backing member for each shoeproviding a ball-aud-socket mounting therefor,v permitting rocking ofeach shoe to form with said surface a wedge-shaped lubricant pocket, alubricant passage through each y shoe and its backing member andcommunicating with the. associated pocket, means for supplying lubricantunder pressure to said passages, and

means for independently adjusting the pressure 7.. Infa bearingAconstruction of scribed, a rotary member having a. bearing surface, aplurality of segmental shoes arranged in a circular series about saidsurface and each rockably supported to form with said surface awedgeshaped lubricant pocket, means for supplying lubricant underpressure to each shoe substantially in the line of its support, andmeans for individu- M. SALIPATACOS.

the class del effective on each shoe.

